Round neon light blue ball passing east to west across the sky.

I awoke at approx. 3am as a horse I was preparing to show the next day was very worked up about something out in our yard.  This was fairly unusual behavior for this particular horse so I went out to try and calm her.  I was able to catch her and calm her some and proceeded to sit nearby talking to her to sooth her while watching a round neon light blue ball moving very slowly towards our general direction.  It was impossible to tell the size of the object or the distance from my location as it was a cloudless night in a flat area. I remember not being frightened and having the impression it was quite far away. The  light slowly proceeded in a slight arc from east to west (still appearing to be getting closer but quite distant) for about 30 minutes as I watched.  Finally it disappeared behind a single tree.  I waited for quite some time for it to reappear on the other side, but it did not.  I am now an aircraft specialist stationed at a military base with substantial air activity and would guess that the light was at approximately 3000' agl.  It was not an airplane.